The advantage in the selloffs of 2008 and 2011 for the S&P 100 (OEF), a group of the biggest stocks in the index, versus the S&P 500 was 1%-2%. That’s negligible in light of the risk in attempting to time it right and, for smalltime investors, trading costs. One reason: Your large-cap fund is already heavily tilted toward the market’s biggest companies.

It’s certainly true that the market’s biggest are on a remarkable streak of bad luck — one that will turn around at some point. Only part of the lag can be chalked up to Apple (AAPL). Here’s a chart of megacap underperformance lately with and without Apple:

About Focus on Funds

As exchange-traded funds and other investing vehicles have ballooned in number, the task of figuring out what works well and what doesn’t has only gotten harder. Barrons.com’s Focus on Funds looks under the hood of ETFs, mutual funds and hedge funds for overlooked values, actionable ideas and the latest pitfalls for fund investors.